This invention relates to a ruler device for use in marking-off in which a marking-off line or a center punching is applied to a work prior to mechanical machining such as boring or the like.
The device of this kind which has been used heretofore is such that like the drafting machine, two pieces of rails which are orthogonal are provided on the drawing board and the marking-off pin is shifted orthogonally in two directions, and the marking-off is carried out.
In this device, since one rail is fixed to the drawing board, the work must be placed on the drawing board so that the center line of the work becomes parallel or perpendicular to the rail. The placing of the work in this manner is extremely difficult in case the work is heavy and must be shifted by a crane. Also, the device itself occupies an extremely large space.
An object of this invention is to eliminate the foregoing inconvenience and to provide a ruler device that can be used easily on a large workpiece and also that does not take up the large space.
Namely, the ruler device of this invention is such that the rail is independently provided separate from the drawing board, and the rail is fixed to the surface table that is already installed by means of a magnet, and a proper positional relation of the rail and the work placed on the surface table is obtained by shifting the rail, and furthermore, two pieces of the rails are mutually separatable and when it is not used, it is disassembled so as to be stored in a small space.